Metal-Organic Frameworks (MOFs) have attracted significant attention owing to their structural and chemical diversity. MOFs are compounds with a porous crystalline structure that contain metal ions that cross-link with organic linkers in various coordination networks that form one-, two-, or three-dimensional structures. MOFs have a high surface area, large pore volumes, and various pore dimensions and topologies that make MOFs superior to other porous materials for a variety of applications. MOFs are conventionally synthesized using liquid batch methods in various solvents or aqueous solvents under so-called solvo-thermal or hydro-thermal conditions. Many MOFs are prepared in pure N,N-diethylformamide (DEF) or N,N-dimethylformamide (DMF) or a combination of solvents that include DMF which decompose at reaction temperatures between 50° C. and 250° C. generating an amine base that deprotonates functionalities of the organic linker to form the selected metal-organic framework (MOF).
However, conventional batch synthesis of MOFs has well-known and significant disadvantages. It is well known, for example, that liquid batch synthesis of MOFs produces partially formed products, unreacted products, and contaminates that cannot be removed from the solvents. Contamination of solvents and liquid precursor materials means solvents cannot be reused and must be replaced after every production run. Solvents alone account for nearly half of the total cost of a MOF product presently. Thus, following separation from the batch liquid, MOF crystals must be activated prior to use using a multi-step solvent exchange process that removes contaminants, partially reacted (or unreacted) products, and high-boiling solvents from the pores of the resulting MOFs—a slow and costly procedure.
Another disadvantage of conventional batch synthesis is the production of low-purity MOFs. Only a small fraction of a desired MOF product is produced. And, presence of secondary or interpenetration frameworks can exist within pores of a first framework, which are difficult to detect. Presence of secondary frameworks can block existing pores which affects properties of the resulting MOF. In addition, batch methods do not operate continuously, and have limited or no scalability, and as such are less likely to be cost-effective methods for MOF production. Batch methods used to produce MOF particles are also small or undersized, which limits potential applications or requires expensive post-processing to correct and are typically also very slow. Typical synthesis times are in excess of 24 hours on average and can be as long as 3 weeks or more.
Various methods have been proposed in the literature for combining MOFs with other functional matrix materials to form new multi-functional MOF composites that exhibit desired properties in order to broaden potential applications. However, controlling integration of the various and disparate individual components in suitable MOF composites is still undergoing. Thus, despite their tremendous potential, deployment of MOFs in commercial or industrial applications is currently limited by a lack of technologies and processes that permit synthesis and activation of these materials in suitable quantities, at desired quality and at costs that would make industrial applications feasible. New systems and processes are needed that address the various limitations of conventional syntheses and permit production of Metal Organic Frameworks (MOFs) and MOF composites on a large scale. The present invention addresses these needs.